Feature request: Pass files to merging tool when copying

When you copy/move files and destination file already exists, a dialog window appears to ask you what to do. In that window you can double click file icons to show source or destination file so you can see what will overwrite what.
What about an option to compare these file using merging tools like WinMerge (of course only when copying text files)? There could be a button that would pass apt parameters to merging tool to compare / change them.

This should also work for FTP sites.

If you have Beyond Compare you can do this by right-clicking the icons and using the BC commands in the context menu.

I got used to WinMerge, anyway I think they both work the same, standardized way - just get two arguments with file paths.

  1. I can't get it work with FTP sites. I mean, if FTP is set to source it works (I select one file in src lister and another file in dest lister and click my "compare" button). But when FTP is destination lister, then only local file is displayed in merging tool (tested in WinMerge and BC).
    My button code:
C:\Program Files (x86)\WinMerge\WinMerge.exe {filepath$} {filepathdest} 
  1. It's very nice that I can double click those file icons to view file I'm copying/overwriting. Anyway, I thought it would be even more practical to compare these files so I can see what changed and just before commiting changes to FTP website make sure I'm doing what I want/need/should do.

PS. Oh, I just figured out what you were taking about. Just found out "select left file for compare" and (after selecting left file) "compare to" options in context menu. The bad news is it doesn't work for (s)FTP sites (context menu entry doesn't show).